A solid laser, semiconductor laser and gas laser having a large output and a small size, which radiate an ultraviolet ray, visible light or infrared ray having a wavelength of from 300 to 1,200 nm, have become easily available, and these lasers are very advantageous for a recording light source used in the direct plate-making based on digital signals, for example, from a computer.
Various investigations on recording materials sensitive to such laser beams have been made. Representative examples of the recording materials include first recording materials capable of being recorded with a infrared laser having a wavelength of not less than 760 nm, for example, positive working recording materials as described in U.S. Pat. No. 4,708,925 and negative working recording materials of acid catalyst crosslinking type described in JP-A-8-276558 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”), and second recording materials responsive to an ultraviolet ray or visible light laser having a wavelength of from 300 to 700 nm, for example, negative working recording materials of radical polymerization type as described in U.S. Pat. No. 2,850,445 and JP-B-44-20189 (the term “JP-B” as used herein means an “examined Japanese patent publication”).
On the other hand, recording materials responsive to light having a short wavelength of not more than 300 nm are especially important for photoresist materials. In recent years, the degree of integration is more and more increased in integrated circuits, and the fabrication of super-fine patterns composed of lines having a width of finer than a half micron has been required in the production of semiconductor substrate, for example, VLSI. In order to fulfill such requirements, the wavelength of light source for an exposure apparatus used in photolithography is more and more shortened and the use of a far ultraviolet ray or an excimer laser (e.g., XeCl, KrF or ArF) has been investigated. Further, the formation of super-fine patterns by an electron beam has been started to investigate. Particularly, the electron beam is regarded as a promising light source for the next generation pattern formation techniques.
A subject common to all of these image recording materials is how a film strength of a photosensitive layer and preservation stability can be stood together.
The recording material for lithographic printing plate is required to have a high film strength in view of printing durability. However, it is difficult for the film strength of a photosensitive layer to consist with the preservation stability, and satisfactory results thereon have not been obtained in the prior art. Thus, novel techniques to solve the problem have been desired.